干旱期灌溉与施化肥对半干旱区春小麦产量及其水分利用效率的影响

Irrigation and fertilizer application of dry-period affect yield of spring wheat and water use efficiency in semi-arid regions

以黄土高原半干旱区主要作物春小麦为研究对象,采用田间小区试验与定量分析相结合的方法,研究了干旱期控制灌溉和施化肥对春小麦产量形成及其水分利用效率的重要影响.本试验设计包括干旱期灌溉供水30,60,90 mm和不灌溉等四种水处理,施肥处理包括施化肥(磷酸氢二铵248kg/hm^2)和不施肥两种处理,二者相互交叉配置共组成八种水肥处理.研究结果表明:干旱期灌溉与施肥处理具有显著的交互作用(P<0.05).与无灌溉处理相比,干旱期灌溉能产生更大更深的根系和更大的叶而积指数(LAI).与相应无灌溉处理相比,不施肥下干旱期灌溉30,60,90 mm可导致0～120 cm土层平均根生物量最大值(开花期)分别增加了30.6%,49.5%,74.4%,LAI最大值(开花期)分别增加了12.3%,28.1%,45.1%;施肥条件下平均根生物量最大值分别增加了31.7%,52.3%,75.1%,LAI最大值分别增加了13.6%,28.0%,47.1%.这表明干旱期灌溉与施肥具有克服干旱胁迫促进作物生长发育的显著效果.干旱期灌溉与播前灌溉等相比,具有增加产量和提高水分利用效率(WUE)的显著效果.其中不施肥下干旱期灌溉30,60,90 mm处理下籽粒产量分别达到1 849.5,2363.4,2871.2 kg/hm^2,比相应的无灌溉的产量(1326.8 kg/hm^2)分别增加了39.4%,78.1%,116.4%,WUE提高了26.6%,48.2%,66.1%;施化肥且干旱期灌溉30,60,90 mm,其籽粒产量分别为2 104.9,2 715.7,3 318.6 kg/hm^2,比相应只施化肥不灌溉的籽粒产量(1465.2 kg/hm^2)分别增加了43.7%,85.3%,116.5%,WUE分别提高了30.6%,54.4%,74.2%.各处理下的最高籽粒产量(3318.6 kg/hm^2)、最大水分利用效率(8.516kg/hm^2·mm))在干旱期灌溉90 mm且施化肥的组合处理下一致达到,表明这是半干旱区的一种高产高效的农田管理措施.以上研究结果为半干旱区集水农业发展提供了科学依据.

The main crop of loess plateau in semi-arid region, spring wheat is taken as the research object, by using field experiment and quantitive analysis, the effects on yield and water use efficiency of spring wheat of dry-period irrigation and fertilizer application are examined. The study includes four water and two fer- tilizer treatments： with 30, 60, 90 mm irrigation and without irrigation, fertilizer application （（NH4）2HPO4） and without fertilizer application. Both cross-configuration, they composes eight kinds of treatments. The re- sults indicate that there was a significant interaction between irrigation and fertilization. Dry-period irrigation resulted in larger and deeper root systems and larger leaf area index （LAI） compared with the non-irrigated treatments. With 30, 60, 90 mm dry-period irrigation, the average of maximum root biomass in 0~.,120 cm soil layer （florescence） are 30.6%, 49.5% and 74.4% higher than that of non-irrigated treatment; The maximum LAI are 12.3%, 28.1% and 45.1% higher than that of non-irrigated treatments （florescence）. With fertilizer appli- cation, the average of maximum root biomass are 31.7%, 52.3% and 75.1% higher than that of non-irrigated treatment; The maximum LAI are 13.6%, 28.0% and 47.1% higher than that of non-irrigated treatments. This shows that dry-period irrigation can help crop overcome drought stress and promote growth and development significantly. Compared with pre-sowing irrigation, dry-period irrigation has the remarkable effects on enhancing yield and water use efficiency of spring wheat. Without fertilization, the grain yield in 30, 60, 90 mm dry-period irrigation are 1849.5, 2 363.4, 2 871.2 kg/hm2 respectively, being 39.4%, 78.1% and 116.4% higher than that of non-irrigation （1326.8 kg/hm2, the WUE increased by 26.6%, 48.2% and 66.1% respectively. With fertilization, the grain yield in 30, 60, 90 mm dry-period irrigation are 2 104.9, 2715.7, 3318. kg/hm2 respectively, being 43.7%, 85.3% and 116.5% higher than that of non-irrigation （1465.2 kg/hm2, the WUE increased by 30.6%, 54.4% and 74.2% respectively. The highest yield （3318.6 kg/hm2 and WUE （8.516 kg/（hm2.mm） consistently ocurred in the combination of 90 mm dry-period irrigation and fertilization, suggesting that this is a beneficial agricultural management practices in semi-arid regions. The above results provide scientific basis for rainwater harvesting agricuture development in semi-arid regions.